The Guru always said that due to the way the Northstar was built it is very unlikely to see coolant in the oil when a head gasket fails. If he explained further, I don't remember what he said.

09-30-08, 07:42 PM

zonie77

Re: Blown Head Gasket? how to check

Quote:

Originally Posted by STSj90

Ive always understood that this coolant in oil/oil in coolant. Is highly Unlikly to happen on the Northstar.

Right, the oil passages are located far from the coolant passages. Head Gaskets can leak in many different ways. The old coolant in the oil did not always happen, even with older engines, and less with newer engines.

11-02-08, 11:55 AM

lamistar

Re: Blown Head Gasket? how to check

I have a modified, no nitrous, 93 Eldorado running low 14's high 13's that had a similar problem. Note that some of these earlier Northstars also had insert problems that caused the head bolts to come loose, causing the cylinder head to separate from the engine block. In my case, it wasn't the head gasket or the insert issue. Also remember that the Northstar is a high performance V8 that runs fine at normal operating temps between 210 and 225 degrees. But the moment that you see a consistent overflow of coolant from the resevoir, you definately have a problem.

The following steps solved my problem as the root cause was air entering the cooling system, not from a head gasket or cylinder head sealing problem but from a faulty water pump seal. The factory water pump cover and respective seal are junk- the groove that contains the "o-ring" style seal is too small- not to mention, these covers easily crack near the 4 retaining bolts due to overtightening. Check for any white deposits near the water pump cover as this is a good indication you have a leak. What's important here is that a leak at this point will have the most immediate impact to increased coolant system overpressurization: It is here where the water pump sucks coolant from the radiator to the engine when the thermostat opens. A leaky seal at this point will act like a vacuum cleaner and suck a nice amount of engine compartment air along with coolant into the engine- I think we all know what air pockets in a cooling system can do.

Now the solution: Replace the OEM waterpump cover- the new cover has a larger groove and larger gasket or seal. This helps seal the cover better and prevents the "vacuum cleaner" effect I mentioned aboove. While your at it, replace the lower radiator hose & thermostat. Also, make sure you reuse the inner coil or purchase a new one for the lower hose- this is critical as the inner coil prevents a collapsing of the hose. Remember- the pump is sucking from the radiator to the block at this point. Without this internal coil the lower hose has a good chance on collasping on itself preventing proper coolant flow. Who knows, this may also be part of your problem as many people don't reuse the coil after replacing the lower hose- for some reason, almost all replacement hoses don't come with the inner coil support. Also, when attaching the new cover to the housing, put a washer on each bolt to help absorb some of the torque as you tighten them- this will help prevent cracking the cover.

Good Luck!!!

10-28-09, 10:04 PM

evvdeville

Re: Blown Head Gasket? how to check

why are there not class lawsuits over the northstar blown head gaskets and stripped threads. Seems to happen a lot.

I would go to this website and try their sealant. I used it on a 6 cylinder chevy a while back (Head Gasket Repair) and it worked for over a year before I sold it. Now they have "Head Gasket Fix" even better.....what do you have to loose???

I would go to this website and try their sealant. I used it on a 6 cylinder chevy a while back (Head Gasket Repair) and it worked for over a year before I sold it. Now they have "Head Gasket Fix" even better.....what do you have to loose???

And NO I do not work for Bar's! :)

Good Luck

Dale

Here we go again...

10-28-09, 10:54 PM

dakrri

Re: Blown Head Gasket? how to check

All's I'm saying....... what is the worst that can happen.

10-28-09, 11:00 PM

Ranger

Re: Blown Head Gasket? how to check

It won't work on a Northstar. Do a search and read rfishings lengthy and painful Thermogasket thread.

10-28-09, 11:06 PM

00 Deville

Re: Blown Head Gasket? how to check

Quote:

Originally Posted by dakrri

All's I'm saying....... what is the worst that can happen.

Dale, Adding the miracle HG repair in a bottle has been beat to death around here for a long time. The short version of the story is it is a very short term fix if any fix at all on a N*. This stuff clogs up the radiator, heater core and cooling passages.

10-28-09, 11:14 PM

Ranger

Re: Blown Head Gasket? how to check

That is the same stuff they poured into the crankcase so seize engines on the vehicles that where turned in on the CARS program.

10-29-09, 12:02 AM

dakrri

Re: Blown Head Gasket? how to check

I agree..... it only buys you time (if it even works at all on a N*) but it gives you time to shop around for the right price and an honest tech to do the repair correctly.

I happened to have good results on a winter beater with Bar's. I bypassed the heater core for the first 500 miles, and then flushed the system, it never clogged anything except the head gasket

As far as "the miracle in a bottle" look at all the people who think synthetic oil will make their engine problom free....save the money on oil, and keep up "all" the other maintenance on your car. The cooling system is a biggy!

Just my 2 cents worth.......

Dale

10-29-09, 01:13 AM

Shea_G

Re: Blown Head Gasket? how to check

How hard would it be to swap in a lt1, ls# or similar engine?

10-29-09, 07:43 AM

Submariner409

Re: Blown Head Gasket? how to check

It's not hard: It's impossible.

Head gasket repair liquids are designed to work under some pretty specific conditions, and one of those is that the head-block clamping/bolt pattern is good so the liquid can fill a void and harden. The Northstar problem is that the head bolts are slowly coming out of the block from compromised threads, so the head/block gasket space is never static: it is constantly increasing. It's sort of like trying to pour cement into the San Andreas fault: the fault is dynamic, expanding constantly, and there is not enough cement on (in) earth to seal it.

11-07-09, 02:15 PM

hesermon

Re: Blown Head Gasket? how to check

AC, you are describing my 97 STS. After a new thermostat, wp, gaskets at the heater pipes on the block, new radiator, lots of pressure testing, several gallons of antifreeze, and multiple use of every cuss word I've ever heard, we did a combustion test. This showed positive even though the car runs great and and no fluid mixing it was a blown head gasket. In my case new head gaskets were cost prohibitive so I used "Blue Devil". It says right on the bottle not to use in Northstars but on the advice of a couple caddy guys (and nothing really to lose) I gave it a try. 5000 miles later no overheating, no boiling over, no problems except a leak behind the front driver side wheel. I can't figure this out because as far as I know there is nothing to leak over there. Not telling you to use this product, only that I did and so far, so good. Good luck!

12-07-10, 10:36 AM

a027418

Re: Blown Head Gasket? how to check

Hello all. Does anyone know which years the Northstar has this head gasket problem? Are any years better than others? Are any models better than other. Thanks, Joe